Raducanu and Swiatek make fast starts at Indian Wells
Neither Liu nor the breezy conditions on Stadium Court troubled Swiatek, who is seeking to become just the second woman -- after Martina Navratilova in 1990-91 -- to successfully defend her title at the prestigious combined WTA and ATP Masters 1000 hard court tournament.
Swiatek roared through the first set, winning 25 of 32 points.
She didn't have things quite so much her own way in the second, although she never faced a break point. Liu did manage to save a match point as she finally held serve in the penultimate game.
The crowd roard when Liu -- facing a top-ranked player for the first time -- slipped a forehand passing shot under Swiatek's guard on game point.
It brought a relieved smile to the American's face, but Swiatek closed it out in the next game after 65 minutes.
"For sure Claire used that moment when I didn't play as aggressive that I should be, but I'm pretty happy that I was able to close it out pretty fast," said Swiatek, the reigning French Open and US Open champion who was surprised in the round of 16 at the Australian Open in January.
Since then, the 21-year-old from Warsaw has successfully defended her title in Doha and reached the final in Dubai.
Men's top seed Carlos Alcaraz was scheduled to open his campaign on Saturday night, taking on Australian qualifier Thanasi Kokkinaki.
The 19-year-old Spaniard, whose US Open triumph last year saw him become the youngest-ever world number one, missed the Australian Open as a string of injuries sidelined him for four months.
He returned to win the title in Buenos Aires before falling in the final at Rio de Janeiro, where he was hindered by a hamstring strain that prompted him to pull out of the ATP tournament in Acapulco.
Taylor Fritz opened his title defence against fellow American Ben Shelton.
Fritz, who defeated Rafael Nadal in the title match last year, is coming off a title at Delray Beach that saw him become the first American man in the top five of the world rankings since Andy Roddick in September of 2009.
Former world number one Andy Murray, grinding his way back after hip replacement in 2019, faced lucky loser Radu Albot. The winner will face Jack Draper, who won an all-British battle with 24th seed Daniel Evans 6-4, 6-2.
Raducanu rallies
Emma Raducanu, Britain's 2021 US Open champion, shook off a flare-up of her right wrist trouble to beat Australian Open semi-finalist Magda Linette of Poland 7-6 (7/3), 6-2.
Britain's Raducanu -- who has been slowed by wrist pain, an ankle injury and a bout of tonsillitis this year -- received treatment on her right wrist during the match but dug in to oust the 20th seed in one hour and 50 minutes.
It marked the first time since September in Seoul that Raducanu has put together back-to-back match wins -- one of which was a quarter-final triumph over Linette.
Raducanu rallied from 4-1 down in the opening set to force the tiebreaker. She broke Linette in the fourth game of the second set and saved two break points in the next game, eventually putting it away with a stinging forehand down the line.
Raducanu said her wrist trouble was "manageable," and she was pleased that she was feeling better physically than she did in the first round, when she was still feeling the effects of the illness that forced her out of a tournament in Texas last month.
"I was so out of it, I didn't really know what was going on," she said. "Today, I was so pleased with the way I fought because Magda played really high level (and) some things that were working in the past weren't working today, and I adapted."
In another early match, 67th-ranked Czech Karolina Muchova surprised two-time Indian Wells champion Victoria Azarenka 7-6 (7/1), 6-3.
